Motorcycle

ABSTRACT

The invention prevents a decrease in a bank angle while cornering and reduces damage incurred to an AMT mechanism when tumbling over. A motorcycle  1  includes a cylinder block  47  of an engine, a crankcase  49  located below this cylinder block  47 , a transmission  55  located behind this crankcase  49  and provided with a multistage shifting mechanism having multistage change gears, a clutch for connecting/disconnecting transmission of rotation when shifting the change gears of this transmission  55 , and an AMT mechanism  63  for automatically actuating this clutch and shifting the change gears of the transmission  55 . Since this AMT mechanism  63  is located behind the cylinder block  47  and above the transmission  55 , a decrease in the bank angle is prevented while cornering, and fatal damage to the AMT mechanism  63  can be reduced when the motorcycle  1  tumbles over.

TECHNICAL FIELD

The present invention relates to a motorcycle with improvement inplacement of an automatic transmission control device.

BACKGROUND ART

In a conventional motorcycle, rotation of a crank shaft inside acrankcase cover of an engine is changed by a transmission. In thistransmission, a multistage shifting mechanism including a main shaft ofa gearbox, a drive shaft, and multistage change gears is housed therein,and a clutch for connecting/disconnecting transmission of rotation whenshifting the change gears is provided. Moreover, an automatictransmission control device for automatically actuating the clutch andshifting the change gears of the transmission, in other words, an AMT(automated transmission) mechanism is provided.

This AMT mechanism includes a clutch actuator for actuating the clutch,a shift actuator for shifting the change gears of the transmission, andother components necessary for the AMT. The AMT mechanism is eithersemi-automatic or full-automatic. This AMT mechanism is provided besideand below the crankcase cover in a car width direction.

Incidentally, in the conventional motorcycle, the AMT mechanism isprovided beside and below the crankcase cover in the car widthdirection, thus there have been problems that the AMT mechanism hits theground in the first place and suffers damage when banking the motorcyclewhile cornering, and that a bank angle of the motorcycle is limitedwhile cornering because of the AMT mechanism hitting the ground.

Moreover, there has been a problem that the AMT mechanism is susceptibleto damage when the motorcycle tumbles over, and it is highly likely thatshift change becomes impossible.

DISCLOSURE OF THE INVENTION

The present invention has been accomplished to solve the foregoingproblems, and an object thereof is to provide a motorcycle which iscapable of preventing a decrease in the bank angle while cornering, andof reducing damage incurred to the AMT mechanism when tumbling over.

A motorcycle according to a first aspect of the present invention forattaining the object is a motorcycle including a cylinder block of anengine, a crankcase located below this cylinder block, a transmissionlocated behind this crankcase and provided with a multistage shiftingmechanism having multistage change gears, a clutch forconnecting/disconnecting transmission of rotation when shifting thechange gears of this transmission, and an automatic transmission controldevice for automatically actuating this clutch and shifting the changegears of the transmission, which is characterized in that the automatictransmission control device is located behind the cylinder block andabove the transmission.

According to the motorcycle of this first aspect, since the automatictransmission control device is located behind the cylinder block andabove the transmission, a decrease in a bank angle is prevented when themotorcycle performs cornering. Moreover, fatal damage to the AMTmechanism is reduced when the motorcycle tumbles over.

A motorcycle according to a second aspect of the present invention forattaining the object is a motorcycle including a cylinder block of anengine, a crankcase located below this cylinder block, a transmissionlocated behind this crankcase and provided with a multistage shiftingmechanism having multistage change gears, a clutch forconnecting/disconnecting transmission of rotation when shifting thechange gears of this transmission, and an automatic transmission controldevice for automatically actuating this clutch and shifting the changegears of the transmission, which is characterized in that the automatictransmission control device is located in a space between two left andright straight lines respectively connecting a tread surface of a tireof the motorcycle and tips of left and right steps in a car widthdirection for allowing a driver to step on.

Therefore, as similar to an operation of the motorcycle according to thefirst aspect of the present invention, the decrease in the bank angle isprevented when the motorcycle performs cornering. Moreover, the damageto the AMT mechanism can be reduced when the motorcycle tumbles over.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a left side view of a motorcycle according to an embodiment ofthe present invention.

FIG. 2 is an enlarged left side view of an engine unit of FIG. 1.

FIG. 3 is an enlarged right side view of the engine unit of themotorcycle of FIG. 1.

FIG. 4 is a rear view of a shift actuator and a clutch actuator viewedwhen the motorcycle of FIG. 1 is oriented to a traveling direction.

FIG. 5 is a front view of a motorcycle of an embodiment of the presentinvention.

FIG. 6 is a schematic drawing of switches on a clip side of a lefthandle.

FIG. 7 is a system diagram of an AMT mechanism showing the embodiment ofthe present invention.

BEST MODES FOR CARRYING OUT THE INVENTION

In the following, description will be made on a motorcycle according toembodiments of the present invention with reference to the drawings.

It is to be noted that up and down, left and right, and front and backin this embodiment mean left and right, front and back, and up and downin a state where a driver is seated on a seat of a motorcycle accordingto the embodiments so as to face handle thereof.

Referring to FIG. 1, a motorcycle 1 according to this embodiment has astructure in which a car body frame 3 is connected to a head pipe 5 anda rear frame 9 extending obliquely backward is connected to rear ends ofa left and right pair of tank rails 7. A fuel tank 11 is provided abovethe tank rails 7, and an engine unit 13 is provided therebelow. A mainseat 15 is provided in front of the rear frame 9.

Meanwhile, a front fork 17 is pivotally supported by the head pipe 5,steering handle 19 are provided on an upper end of the front fork 17,and a front wheel 21 is provided on a lower end thereof. Moreover, arear arm 25 is pivotally supported as vertically swingable by a rear armbracket 23 below the rear ends of the tank rails 7 through a pivot shaft27, and a rear wheel 29 is provided at a rear end of the rear arm 25.Moreover, the rear arm bracket 23 is provided with a step bracket 31 soas to protrude backward, and steps 33 for placing feet of a driver areprovided on the step bracket 31 outward in the car width direction.

Meanwhile, a cowling 35 is provided on the car body frame 3. Thiscowling 35 includes an upper cowling 37 for covering a front part of thesteering handle 19, and a lower cowling 39 for covering a front part andleft and right sides of the tank rails 7 as well as left and right lowerparts of the engine unit 13. Here, the upper cowling 37 is supported bythe car body frame 3 through an unillustrated stay and adopts astructure by which a front face of a front part of the car body and bothside faces in the left-and-right direction are formed, and a screen 41made of a transparent material, a head lamp 43, and the like are fittedto an upper part of a front side of the car body.

Moreover, the rear frame 9 is provided with side covers 45 for coveringleft and right sides of the main seat 15 and an upper part of the rearwheel 29.

In this embodiment, the engine unit 13 is of water-cooled, four-cycle,parallel four-cylinder type, in which a cylinder axis of a cylinderblock 47 is slightly inclined to the front part of the car body, and acrankcase 49 located below the cylinder block 47 for housing a crankshaft is hung across and supported by the car body frame 3 toward thecar width direction. Here, a cylinder head 51 and a head cover 53 arestacked and joined together on an upper face of the cylinder block 47.

Meanwhile, a gearbox case 55 (a transmission) for housing a multistageshifting mechanism which includes a main shaft of a gearbox providedparallel to the crank shaft, a drive shaft, and multistage change gears,is integrally formed at a rear part of the cylinder block 47. Thistransmission 55 is provided with a clutch for connecting/disconnectingtransmission of rotation when shifting the change gears. The crankcase49 is joined to lower surfaces of the cylinder block 47 and thetransmission 55.

Moreover, a driven sprocket 59 is provided to a spindle 57 whichrotatably supports the rear wheel 29 at the rear end of the rear arm 25.A chain 61 is wound around this driven sprocket 59 and an unillustrateddriving sprocket which is fixed to the drive shaft of the engine unit13. In this way, power of the engine is transmitted to the rear wheel 29through the chain 61.

A hydraulic automatic transmission control device 63 (hereinafterreferred to as an “AMT mechanism”) in the motorcycle 1 will bedescribed.

The AMT (automated transmission) mechanism 63 is configured to actuatethe clutch and shift the change gears of the transmission 55automatically, and includes a clutch actuator 65 (see FIG. 3) foractuating the clutch, a shift actuator 67 for shifting the change gearsof the transmission 55, and other components necessary for the AMT.Here, this AMT mechanism 63 is either semi-automatic or full-automatic.

Referring to FIG. 2 to FIG. 4, the AMT mechanism 63 is located behindthe cylinder block 47 and above the transmission 55.

For example, the shift actuator 67 is located on the left side in atraveling direction of the motorcycle 1 and above the transmission 55,and is configured to actuate the multistage shifting mechanism insidethe transmission 55 by use of a link mechanism composed of a rod 69 anda lever 71 as shown in FIG. 2 and FIG. 4. Meanwhile, the clutch actuator65 is located on the right side in the traveling direction of themotorcycle 1 and above the transmission 55, and is configured to shiftthe clutch inside the transmission 55 by use of a link mechanismcomposed of a rod 73 and a lever 75 as shown in FIG. 3 and FIG. 4.

Here, a system of the AMT mechanism 63 will be described in detail.

Referring to FIG. 6, a shift switch 79 is provided on a grip side of aleft handle 77, for example. This shift switch 79 includes an up switch81 and a down switch 83, for example, and is configured to change ashift position of the change gears from a neutral position to a firstgear and the fastest sixth gear, for example, in an increasing ordecreasing direction by manual operation of a driver. Moreover, the gripside of the left handle 77 is also provided with an AMT switch 85, aturn signal 87, a horn 89, and a light switch 91. Note that the AMTswitch 85 is configured to switch a gear shift operation to be operatedeither in a semi-automatic mode or in a full-automatic mode.

Referring to FIG. 7, switching of the multistage shifting mechanism aswell as of a clutch 93 is driven by unillustrated hydraulic mechanismsincluding motors, pumps, oil tanks, accumulators, and the like by use ofthe AMT mechanism 63. The clutch actuator 65 is provided with a strokesensor (not shown) for detecting a stroke of the clutch 93 by detectinga position of the rod 73, for example, and the transmission 55 isprovided with various sensors such as a car speed sensor or a shiftposition sensor.

Based on detection data of the various sensors and instructions from theshift switch 79, the clutch actuator 65 and the shift actuator 67 aredriven by an engine controller 95. That is to say, a series of shiftingoperations including disconnection of the clutch 93, shifting of thechange gears, and connection of the clutch 93 are operated automaticallyby given programs and other operation circuits stored in advance in theengine controller 95.

As described above, as a placement structure of the AMT mechanism of themotorcycle as the embodiment of the present invention, the AMT mechanism63 including the clutch actuator 65, the shift actuator 67, othercomponents necessary for the AMT, and the like is located behind thecylinder block 47 of the engine unit 13 and above the transmission 55.

For this reason, when the motorcycle 1 gets a flat tire upon cornering,since the AMT mechanism 63 is located behind the cylinder block 47 andabove the transmission 55, it is possible to avoid a possibility thatthe AMT mechanism 63 hits the ground even when the motorcycle 1 istilted to the left side or the right side, for example.

As a result, it is possible to prevent a decrease in a bank angle of themotorcycle 1 while cornering.

Moreover, even if the motorcycle 1 tumbles over, since the AMT mechanism63 is located behind the cylinder block 47 and above the transmission55, it is possible to reduce a possibility that the AMT mechanism 63hits the ground in the first place, and damage incurred to the AMTmechanism 63 can be reduced.

Moreover, when description is made on a placement structure of the AMTmechanism of the motorcycle as another embodiment of the presentinvention, the AMT mechanism 63 is located inside a bank angle θ of themotorcycle 1 as shown in FIG. 5. The bank angle indicates an angle θformed between straight lines BL and BR, which are defined by connectingleft and right parts of tread surfaces of tires 97 on the front wheel 21and the rear wheel 29 to a point SL and a point SR representing tips ofleft and right steps 33L and 33R (a point P represents a intersectionpoint of the straight lines BL and BR).

In FIG. 5, unlike the placement structure of the AMT mechanism of theabove-described embodiment, the shift actuator 67 is located relativelybelow the motorcycle 1 on the left side in the traveling direction (onthe right side in FIG. 5), however is located inside the bank angle θ.Meanwhile, the clutch actuator 65 is also located relatively below themotorcycle 1 on the right side in the traveling direction (on the leftside in FIG. 5), however is located inside the bank angle θ.

Therefore, as similar to the above-described embodiment, an effect ofpreventing the decrease in the bank angle of the motorcycle 1 whilecornering is obtained, and a possibility of fatal damage incurred to theAMT mechanism 63 is reduced even when the motorcycle 1 tumbles over.

It is to be noted that the invention is not limited to the embodimentsdescribed above and can be embodied in other aspects by carrying outappropriate modifications.

1-2. (canceled)
 3. A motorcycle comprising: an engine supported by a carbody frame; a cylinder block constituting a part of this engine; acrankcase located below this cylinder block; a transmission beinglocated behind this crankcase and including a multistage shiftingmechanism having multistage change gears; and a shift actuatorconfigured to shift the change gears of this transmission through a linkmechanism, wherein the shift actuator is formed into a tubular shape andis located behind the cylinder block, above the transmission and infront of a rear end of the transmission so as to allow an axis thereofis oriented in a car width direction.
 4. A motorcycle comprising: anengine supported by a car body frame; a cylinder block constituting apart of this engine; a crankcase located below this cylinder block; atransmission being located behind this crankcase and including amultistage shifting mechanism having multistage change gears; a clutchconfigured to connect/disconnect transmission of rotation when shiftingthe change gears of this transmission; and a clutch actuator configuredto actuate this clutch through a link mechanism, wherein the clutchactuator is formed into a tubular shape and is located behind thecylinder block, above the transmission and in front of a rear end of thetransmission so as to allow an axis thereof is oriented in a car widthdirection.
 5. A motorcycle comprising: an engine supported by a car bodyframe; a cylinder block constituting a part of this engine; a crankcaselocated below this cylinder block; a transmission being located behindthis crankcase and including a multistage shifting mechanism havingmultistage change gears; a shift actuator configured to shift the changeof gears of this transmission through a link mechanism; a clutchconfigured to connect/disconnect transmission of rotation when shiftingthe change gears of this transmission; and a clutch actuator configuredto actuate this clutch through a link mechanism, wherein the shiftactuator and the clutch actuator are located above the transmission andin front of a rear end of the transmission.
 6. A motorcycle comprising:a car body frame including a left and right pair of steps for placingfeet of a driver; an engine supported by this car body frame; a cylinderblock constituting a part of this engine; a crankcase located below thiscylinder block; a transmission being located behind this crankcase andincluding a multistage shifting mechanism having multistage changegears; a shift actuator configured to shift the change gears of thistransmission; a clutch configured to connect/disconnect transmission ofrotation when shifting the change gears of this transmission; a clutchactuator configured to actuate this clutch; and a tire supported by thecar body frame, wherein the clutch actuator and the shift actuator arelocated separately on left and right sides so as to sandwich a center ofthe tire in a space between straight lines respectively connecting atread surface of the tire and tips of the left and right pair of stepsfrom a frontal viewpoint.
 7. The motorcycle according to claim 6,wherein the shift actuator is formed into a tubular shape and is locatedso as to render an axis thereof inclined relative to a verticaldirection.
 8. The motorcycle according to claims 6 or 7, Wherein theclutch actuator is formed into a tubular shape and is Located so as torender an axis thereof inclined relative to the vertical direction.